It may look like a garbled computer message, but its
actually bad news for beef and chicken lovers, especially with the summer cookout season
around the corner.

The snippets are shorthand for half a dozen
potentially cancer-causing chemicals called HCAs, or heterocyclic amines, which are
created when meat, poultry, and fish are cooked at high temperatures.

"We know these compounds can probably cause
cancer in humans," says Elizabeth Snyderwine, Chief of the Chemical Carcinogenesis
Section at the National Cancer Institute (NCI) in Bethesda, Maryland. "What we
dont know yet is how significant a problem they are in the American diet."

Until theres more evidence, "it makes
sense to avoid (HCAs) when we can," says Mark Knize of the Lawrence Livermore
National Laboratory in Livermore, California.

The Culprits

How much HCAs are created depends on how long the
food cooks, at what temperature, and how its prepared.

"Meat and poultry produce the most HCAs
because they contain the most amino acids and creatine, which are converted into
HCAs," says Lawrence Livermores James Felton. "Seafood produces much less,
and plant foods like veggieburgers, fruits, and vegetables little or none."

Grilling, barbecuing, broiling, and pan-frying
are more likely to produce HCAs than baking or roasting, because they generate more heat.
A propane gas grill set on high can reach 640 F, while a typical roasting temperature is
350 .

Cooking with liquidboiling, steaming,
poaching, or stewing, for examplegenerates no HCAs because the temperature never
tops the boiling point of water. Ditto for microwaving, so long as the food is not
overcooked or dried out.

NCI epidemiologist Rashmi Sinha says that
well-done beef, pork, and chicken produce the most HCAs, particularly if theyve been
grilled or barbecued.

"But nowadays, with bacterial infections,
you dont want to tell people to eat rare meat," she says. "You want to
cook it thoroughly, but not at a very high temperature."

While charred meat and poultry contain more HCAs,
you cant always predict which meats have the most. For example:

Fewer
HCAs are found in fast-food burgers because theyre cooked so quickly.
"Theyre not exposed to the high heat over a long time that causes large amounts
of HCAs," says Knize. "There are some, but not what you get off the backyard
barbecue."

Pre-cooking
or marinating cuts HCAs (see "Avoiding HCAs and PAHs").

Sausage
casings and hot dog outer skins also seem to prevent HCAs.

As
meat and poultry shrink, they lose moisture. That pushes HCA-creating chemicals to the
surface, where the heat is more intense. "If you cook the meat and it shrinks 25 to
30 percent, then you start to get higher amounts of HCAs," says Knize.

PAHs: Another Grill Menace

Whenever fat drips on a flame, heating element,
or hot coals, chemicals called PAHs (polycyclic aromatic hydrocarbons) form. The PAHs waft
up in the smoke and can land on the food. They can also form directly on food when
its cooked to a crisp.

"If you throw a steak or hamburger on the
grill and let it get really brownthe fats dripping off it and flames and smoke
are shooting upthats the stuff you dont want to do," says the
NCIs Rashmi Sinha.

As many as 12 of the 18 PAHs found in cooked food
cause cancer in laboratory animals. But proof that they cause cancer in humans is still
elusive. The key to preventing PAHs: Stop the fat from dripping on the heat source (see
"Avoiding HCAs and PAHs").

The Smoking Gun

People who eat more meat have a higher risk of
colon and prostate cancer. Is that because they eat more saturated fat, fewer fruits and
vegetables, or more or less of something else? No one knows. Could it be because they
consume more HCAs and PAHs? Most research has centered on HCAs.

Only one study has asked people how much meat
they ate and how they cooked it, and then waited to see who got cancer.

Among 10,000 Finns monitored for 24 years, women
who reported eating the most fried meat had a 77 percent greater risk of developing cancer
of the breast, endometrium, or ovary than women who ate the least. But men who ate more
fried meat had no greater cancer risk than men who ate less. (The researchers didnt
ask about grilled or broiled meat.)

And six studies have found that people with
breast, colon, stomach, or other cancers had eaten more fried or well-done meats than
similar people without cancer.

But being diagnosed with cancer may have biased
their reporting.

Case Not Closed

"It seems very plausible that HCAs cause
cancer," says Knize. "But its still a long way from proof."

First, "the level of HCAs in food can vary
by two-hundred fold or more, since it depends so much on cooking conditions," points
out Lawrence Livermores James Felton.

Second, people vary in their susceptibility.
About half of all Caucasians in the U.S. inherit a slow-acting form of an enzyme called
NAT2, and that makes them less susceptible to developing cancer from carcinogens like
HCAs.

Put these two factors together "and you
could have a thousand times greater risk of cancer than your neighbor who eats the same
food," says Felton.

Lawrence Livermore has an NCI grant to work on
the HCA puzzle. In the meantime, "I think were on really safe ground to say
that well-done or very-well-done meat is not good for you," says Sinha.

Avoiding HCAs and PAHs

Heres how to minimize your exposure
to HCAs and PAHs. Some of the tips will also help keep harmful bacteria at bay:

WHAT TO COOK

Use lean cuts of meat and poultry.
They produce fewer PAHs because theres less fat to drip on the heating source.

Use fish or shellfish. Most have
less fat than meat, take a shorter time to cook, and seem to create fewer HCAs.

Try tofu or veggieburgers. They
produce very few or no HCAs or PAHs.

Grill or broil vegetables or
fruit. "Weve never seen any of the cancer-causing compounds in grilled
vegetables or fruits because the chemical precursors just arent there," says
Lawrence Livermores James Felton.

HOW TO PREPARE IT

Thaw frozen meat or poultry in the
refrigerator before you cook it. Cooking frozen meat overexposes the surfaces to high
temperatures while the inside warms up slowly.

Cut meat and poultry into small
chunks. They cook faster that way, so theres less time for HCAs to form.

Before grilling or broiling,
pre-cook meat or poultry in the microwave for two to five minutes and throw away the
juice. "By discarding this juice, you can reduce HCAs by 90 percent," says
Lawrence Livermores Mark Knize.

Marinate your meat and poultry.
Marinating for even a few minutes sets up a barrier against heat that dramatically lowers
the creation of HCAs. The marinade ingredients dont seem to matter, but if
youre grilling, less oil means fewer PAHs because less fat drips on the coals (for
recipes, see p. 12). To keep bacteria from growing, keep marinating food in the fridge,
and never add uncooked marinade to the cooked meat or poultry.

HOW TO COOK IT

Try a gas grill (not set on high).
It cooks at a lower temperature than charcoal or wood fires and its easier to
control the temperature.

Use hardwood charcoal. It burns at
lower temperatures than mesquite or other soft woods.

Dont build the biggest bed
of coals in your neighborhood. "Flames will increase the cooking temperature much
higher than radiant heat and produce at least ten times as many HCAs," says Felton.

Instead of spreading the coals
evenly across the bottom of the barbecue, rake them to one side and cook the food on the
opposite side. Or form the coals into a doughnut shape and grill over the center.
"The trick is not to let flames engulf the meat and not to let the fat drip onto the
coals," says Felton.

Place the grill rack or broiler
pan farther from the heat. The food will cook at a lower temperature. "Higher
temperatures and overcooking seem to form more cancer-causing compounds," says Knize.
If you have to cook directly over the heat source, use a drip pan to catch the juices or
cover the grill rack with foil that has holes punched in it.

Avoid eating blackened or charred
food.

Take food off the heat as soon as
its cooked. Dont put cooked food back on the same plate used for raw meat,
poultry, or fish. Dont add pan drippings to sauces or basting liquids.